Generally speaking, you need to wrap appstore iap to c*+ using objective-c**, and wrap google play payments api to c*+ using JNI. There maybe some existing source code in this community, but you need to search it.

@joemanaco I just cloned Avalon for IAP purposes and see that you've updated it for C2Dx 3.x (June 4th), but I'm still using 2.2.4 on the project in question. If I roll back to the Feb. 11th version, should it work for IAP for iOS and Google Play (Amazon would be a bonus)? Also, your documentation for Google Payment is TBD, do you have an update on that or an example project? Thanks much!